Article History
Received: 23 July 2018
Accepted: 22 October 2018
First Online: 3 November 2018
Ethics approval and consent to participate
: The study protocol was approved by the Institutional Review Board of Peking Union Medical College Hospital (protocol number: S-K489), and written informed consent was obtained from all patients or their families for data collection.
: Written informed consent for publication was obtained from all patients or their families at the same time of obtaining consent for data collection.
: The authors declare that they have no competing interests.
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